BULLETIN DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE, SCIENCES DE LA TERRE, 57: 201-215, 1987 BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN, AARDWETENSCHAPPEN, 57: 201-215, 1987 The genus Typocidaris (Cidaroida; Echinoidea) in the Upper Cretaceous of the Maastricht area (Belgium and the Netherlands) by Joris F. GEYS Abstract Unfortunately, isolated skeletal remains of Cidaroida are rarely identifiable. In the past, this has often Compilation of earlier work shows that 19 names have been used for resulted in a profusion of "species", many of which Cidaroida from the Belgian and Dutch Campanian and Maastrichtian. cannot be accepted. In earlier literature, I recorded Most of these have to be rejected or are doubtful, because of the no less than 19 names for Cidaroida from the Maas¬ poor state of préservation of the specimens involved. Typocidaris is trichtian of the area. reintroduced as a separate genus. Four species are described and Maastricht Three of these are discussed; T. ubaghsi is new. characteristic for Danian, rather than Maastrichtian Key-words: Cidaroida, Echinoidea, Maastrichtian, Cretaceous, Bel¬ strata: a frequent error of earlier authors, due to insuf¬ gium, The Netherlands. ficiënt stratigraphical knowledge at that time. Nine taxa have to be rejected, for reasons explained herein. The presence of another four could not be confirmed. Résumé Two species, one of them new, had to be added to the list. This means that the original 19 species are reduced to a mere Pour la description des échinides cidaroides du Campanien et du five, four of them belonging to the Maastrichtien belge et néerlandais, 19 dénominations ont été utilisées genus Typocidaris. A survey of former and present dans le passé. La plupart de celles-ci doivent être rejetées ou ont opinions on the composition of the cidaroid faunas of trait à des espèces insuffisamment connues, ayant été intoduites pour the Upper Cretaceous in the Maastricht area, is given des spécimens de conservation médiocre. Typocidaris est réintroduit in table 1. comme genre indépendant. Quatre espèces sont décrites, dont une, T. ubaghsi, est nouvelle. Mots-clefs: Cidaroida, Echinoidea, Maastrichtien, Crétacé, Belgique, Pays-Bas. Abbreviations used in the text D : diameter of the corona, at the ambitus Introduction h : height of the corona ds : diameter of the apical System dp : diameter of the peristome Fossil remains of Cidaroid Echinoids are by no means rare in Upper Cretaceous deposits. In the Low Coun- Lg : province of Liège NLb province of Dutch Limburg tries, as well as elsewhere, they are frequently found BLb : province of Belgian Limburg as isolated and interambulacral plates. Many hundreds NL : the Netherlands of such fossils are present in almost every important B : Belgium collection, public or private. On the other hand, com¬ DDR : German Democratie Republic plete coronas of Cidaroida are exceedingly rare. Even DK : Denmark D : Fédéral a few plates, remaining in anatomical connection, are Republic of Germany E : Spain an exceptional, and thus valuable fossil. This pheno- F : France menon is partly due to the life habits of Cidaroida, GB United Kingdom of Great Britain and Northern Ireland browsing on hard substrates and hence living in erosio- PL : People's Republic of Poland nal environments (KlER, 1977). The structural SU : Union of Socialist Soviet Republics weakness of the cidaroid test does not favor its préser¬ KBIN : vation either. The stereomes of adjacent plates hardly Royal Belgian Institute for Natural Sciences, Brussels, B. NHMM : Natural History Museum, Maastricht, NL. possess any interlocking processes, so that the plates fall easily apart, after the animal's death and after In the synonymy lists, the conventional signs of A.V. Dhondt (1972) decay of the Connecting tissues (Smith, 1984). have been adopted. 202 Joris F. GEYS Table 1 Cidaroida from the Upper Cretaceous in the Maastricht area, recorded by different authors. Geys herein 1857Bosquet, 1874cotteau, 1897Lambert, 1881Mourlon, 1911Lambert, 1935Smiser, 1965Meijer, Gu Ma Da - Cidaris arenata x x - baylei x ciplyensis x x x — — danica x x x x faujasi x x x x x x — — filamentosa x — — forchhammeri x x x x hardouini x x x x x x lingualis x x o o ornatissima x o o — perornata x — pistillum x x x pseudohirudo x x — — regalis x x o o sceptrifera x x x schlueteri x x — — serrata x x x x x sorigneti x o o subvesiculosa x x x — — ubaghsi x venulosoides x x — — x: recorded; — : doubtful or rejected; O: unconfirmed. Gu: Gulpen Chalk; Ma: Maastricht Chalk; Da: Danian. Typocidaris: independent genus orjunior synonym of Stereocidaris? 05 o E S oî m o 05 a genus, ever JJ in Typocidaris has been well established _c c 0) o o C en — o since it has been erected by Pomel Animais eu en (1883). 05 en >N 'c en CD <d 05 belonging to Typocidaris are characterised by the pos¬ -Q 05 flJ 05 3 CL -C E o _Q T3 session of suturai grooves and almost fully developed Stereo¬ interambulacral scrobicules. Only the uppermost scro- Typocidaris cidaris Temnocidaris bicule in each ambulacrum can be reduced. The genus has been united to Stereocidaris pomel, 1883, by Fell & Pawson (1966), together with Phala- crocidaris Lambert, 1902. I tried to construct a cladogram, illustrating a possible relationship between some Stereocidarinae (Fig. 1). This subfamily separates from stem-Cidaridae by the acquisition of suturai grooves (threshold 1). The sub¬ séquent acquisition of coronal dépressions (threshold 2) gave rise to the genus Temnocidaris cotteau, 1863 (type-species T. magnifica cotteau, 1863). The genus Stereocidaris pomel, 1883 [type-species S. cre- tosa (Mantell, 1835)] arose by réduction of most adapical scrobicules (threshold 3). Fig. 1 Typocidaris in the type-Maastrichtian 203 In this context, Stereocidaris, Temnocidaris and Typo¬ Gulpen Formation, Maastrichtian: 1 impression in cidaris should be considered as separate genera. If flint (coll. L. Indeherberghe). Brunssumer Heide ancestors of Stereocidaris should belong to Typocida¬ (NLb, NL); reworked from Gulpen Formation, Maas¬ ris, the former genus should have to be considered a trichtian: 1 impression in flint (coll. NHMM, n° Boers- subgenus of the latter. This view has already been ma 503). supported by Lambert & Thierry (1910). Our present state of knowledge is insufficiënt however, to Dimensions: permit a final statement. Both flint impressions are fragments. The dimensions Phalacrocidaris does not belong to the Stereocidari- of the J. Jagt specimen are given below: D = 27 mm; nae: it misses the characteristic suturai grooves. In my h = 12 mm; ds = 10 mm; dp = 7 mm; d/D-ratio = opinion, its similarity to Stereocidaris is due to conver¬ 0.44. ds/D-ratio = 0.37; dp/D-ratio = 0.26. gence, rather than to relationship. Description : Moderately small Typocidaris, with a circular peri- Systematic descriptions stome, which is not sunken. Gill slits are absent. Ambulacra are sinuous and wide. Poriferous zones Class Echinoidea Leske, 1778 are slightly depressed. Pores are not conjugate; neural Subclass Perischoechinoidea M'Coy, 1854 grooves are present. The pores of each pair are sepa- Order CIDAROIDA Claus, 1880 rated by a tiny granule, which shows a small, trans- Family CIDARIDAE Gray, 1825 verse groove. The pore pairs are very slightly oblique. Subfamily STEREOCIDARINAE lambert, 1900 Interporiferous areas are fairly wide and densely gra- Genus Typocidaris pomel, 1883 nulated. Vertical, regular series of granules, one on every ambulacral plate, adjoin the poriferous zones. Type-species: Perradially, between these series of larger granules, Cidaris malum Gras, 1848 (original désignation). the remaining space is covered by a very dense, very fine granulation. These small, perradial granules are Typocidaris pistillum (quenstedt, 1852) arranged in horizontal rows : two rows of three to four (Pl. 1, Figs. 1-6) granules on each plate. The granules diminish in size towards the * perradial suture. 1852 Cidaris pistillum, quenstedt, p. 578, pl. 49, At the ambitus, 16 ambulacral fig. 20. plates correspond in . 1910 Cyathocidaris pistillum, Lambert & Thierry, height to one interambulacral plate. There are 5 inter- ambulacral p. 146. plates in a series. Primary tubercles are . 1928 Cidaris Hagenowi, Ravn, p. 17, pl. 2, fig. 8. perforate and non crenulate, except on the adapical . 1928 Cidaris Bolli, Ravn, p. 15, pl. 1, figs. 8, 20. side of tubercles above the ambitus. The areoles are 1939 cf. Cidaris Bolli, kongiel, p. 6, pl. 1, figs. 5-6. slightly conical and moderately sunken. Their distal . 1972 Stereocidaris pistillum, Nestler, pp. 172-180, border has a steep slope, but is neither vertical, nor pl. 1-3. undercut. Scrobicules are surrounded by a full ring of . 1973 Stereocidaris pistillum, kutscher, pp. 108-109, small scrobicular tubercles, which are accompanied figs. 1, 2, 6. by a crescent-shaped élévation on the distal side. At . 1975 Stereocidaris pistillum, nestler, p. 82, fig. 131. the ambitus, a scrobicular (for full synonymy, cf. Nestler, 1972). ring consists of 15 tubercles. The uppermost scrobicule of each interambulacrum is Locus typicus: rudimentary. Extrascrobicular surfaces are covered by Rügen, German Democratie Republic. a very dense, fine granulation. These granulated sur¬ faces completely surround the scrobicules, but are best Stratum typicum: developed interradially. Adradially, a mere two or Schreibkreide, Lower Maastrichtian. three granules separate the scrobicular rings from the sutures. Interradially, the granules are arranged in Occurrences outside the Maastricht-area: irregular series radiating from the scrobicules. In our DDR: Lower Maastrichtian of Rügen (Nestler, specimens, there are no clearly visible furrows 1972); DK: Maastrichtian of Mpn, Sjaelland and Jyl- between these series. Horizontal and interradial sutu¬ land (Ravn, 1928), as Cidaris hagenowi and Cidaris res are depressed. Small, deep dépressions are present bolli\ PL: Maastrichtian of the Lublin-area (Kongiel, on horizontal adapical sutures. 1939), as Cidaris bolli. Diagnostic features: Specimens studied: 1. Interambulacral scrobicules widely separated. Hallembaye (C.P.L.-quarry) (Lg, B); 4.5 m over Loën 2.